A. Field of Invention
This invention pertains to an external defibrillator module arranged and constructed to provide anti-tachyarrhythmia therapy to a patient. In particular, an automatic external defibrillator module is described which has several operational modes including a fully automatic mode in which shocks are delivered without any manual intervention, an advisory mode, a manual mode, and a pacer mode. Moreover, the invention pertains to a defibrillator module which is arranged and constructed for integration with patient monitoring equipment for sharing certain functions and information using a standard or customized protocol.
B. Description of the Prior Art
Defibrillators are devices which apply electric therapy to cardiac patients having an abnormally high heart rhythm or fibrillation. Two kinds of defibrillators are presently available: internal defibrillators which are implanted subcutaneously in a patient together with leads extending through the veins into the cardiac chambers, and external defibrillators which are attached (usually temporarily) to the patient. External defibrillators are used in most instances in case of an emergency, for example, when a patient has either suffered cardiac arrest or when a cardiac arrest is imminent. Typically, therefore external defibrillators are manual devices which must be triggered by a physician or other trained personnel. Internal or implantable defibrillators (and cardioverters) are implanted as a permanent solution for patients having specific well-defined cardiac deficiencies which cannot be treated successfully by other means. They generally operate in an automatic mode.
Commonly-owned U.S. Pat. No. 5,474,574 discloses an external defibrillator. Commonly-owned U.S. Pat. Nos. 4,576,170 and 5,474,574, incorporated herein by reference discloses external defibrillators.
Several patient monitoring systems are presently available in modular form which allow a clinician or other health professional to monitor and display various physiological parameters of a patient. Typically these units include several subassembly modules which cooperate to acquire data from the patient, to store the data electronically and to display information about a patient's physiological status. The systems may also be adapted to generate audible and/or visual alarms when certain criteria are met. Some systems may also be integrated into a communications network covering, for example, a part or even a whole hospital and on which data is exchanged for various purposes. Monitoring systems of this kind are available from GE Marquette Medical Systems of Milwaukee, Wis.; Agilent Technologies of Andover, Mass.; Spacelabs Medical of Redmond, Wash., and many other companies. However, typically these systems are passive in that their main purpose is to monitor, collect information and generate alarms. These systems cannot provide therapy.